The present invention relates to a recording control technique in an information recording device and an information recording system, and more particularly to a technique for backing up data utilizing a mass or large-capacity storage device.
Known information processing systems, such as a personal computer or work station, can include a streaming tape device such as cassette streamer or a mass storage device such as DAT (digital audio tape recorder) used for backup of a large volume of data (for example, a hard disk drive). Recently the remarkable improvement in storage capacity of a medium-exchangeable storage device, such as a DVD-RAM or the like, provides storage capacity per medium equivalent to the storage capacity of a streaming tape device or DAT.
Thus, large-capacity medium-exchangeable storage devices such as a DVD-RAM or the like may be used as a backup device. There are, however, problems with such applications. Namely, the destination for the backup utility software associated with the operating system (OS) is targeted to the device for its use as backup device. Therefore, if a medium-exchangeable storage device is assigned to be a backup storage device as it is, its use as a storage device in an ordinary file system becomes difficult or impossible, thereby diminishing the availability of the large-capacity medium-exchangeable storage device.
If the medium-exchangeable storage device is forced into the shared use as a backup device and for ordinary file system use, there is a possibility that a backup operation will cause overwriting of data in the ordinary file system, resulting in lost data.
These problems are not limited to a data backup application. A similar problem may arise in an application in which multimedia data including picture data, audio data, etc. Namely, a specified application can involve a similar problem because the backup performance is usually realized by use of a specific data format instead of an OS standard file system.
This invention provides a technique for enabling shared use of a medium-exchangeable storage device as a data backup and as an ordinary file system, thereby improving the availability of the medium-exchangeable storage device, while maintaining its backup performance. Further, the invention provides a technique for enabling the shared use of a medium-exchangeable storage device as a data backup and as an ordinary file system without causing risk of data being lost.
In one embodiment, this invention provides each recording management unit, such as any medium-exchangeable storage device, recording drive, recording medium or the like, with data type control information indicating whether that recording management unit is to be used for a specified application. When an access request is generated to a recording management unit provided with data type control information indicative of the use of the recording management unit, the type of generated access request is compared with the previously set data type control information. Where the generated access request is an access request other than the specified application, a response indicative of access inhibition is made to the generated access request.
In a disk changer system provided with a plurality of exchangeable (or removable) recording media and accommodating recording media in a cartridge, each exchangeable recording media can be set with data type control information indicative of whether that recording medium should be used for the purpose of a particular application.
With the above approach in which a comparison for each recording media is made between the type of application making access to that media and the data type of the media being accessed, access is permitted only if the coincidence is obtained between both the types. Typically, a control exclusive of an OS standard file system access is enabled. This enables the coexistence of a standard backup system and a file system specific to a particular application becomes possible.